There are a number of access control systems, which often have been difficult enough to hinder their use. Systems as described in aforementioned patent application Ser. No. 10/802,658 can lead to better use of access control systems, specifically to a great increase in varying access control settings for different documents. Systems as described in aforementioned patent application Ser. No. 11/308,636 can lead to safer use of references in documents under access control, and in doing so to a noticeable share of documents which contain and are processed for access dependent contents. Systems as described in aforementioned patent application Ser. No. 11/308,989 can ease correct and safe handling of confidential information when multiple users are coming together and working together with a number of documents.